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| United States Patent |
6,062,324
|
|
Hipp
|
May 16, 2000
|
Fluid operated vibratory oil well drilling tool
Abstract
An impact driven oil and gas well tool for use with an elongated tubular
string having a central flow conveying bore is provided for channeling
pressurized fluid to the tool body. The apparatus further includes an
elongated longitudinally extending tool body having a connecting end
portion at its upper end for connecting the tool body to the pipe string.
A fluid chamber in the tool body is provided that is in fluid
communication with the pipe string bore. A stem is reciprocally movable
within the tool body in a telescoping fashion. The stem includes a lower
end portion for carrying a working member such as a drill. A pressure
responsive valve is provided for controlling relative movement of the stem
and the tool body. An anti-chatter annular sleeve is positioned in the
fluid chamber and about the valve member. A spring extends between the
sleeve and the valve member for holding the valve member off the seat
until a predetermined flow rate through the tool body is reached.
| Inventors:
|
Hipp; James E. (New Iberia, LA)
|
| Assignee:
|
Baker Hughes Incorporated (Houston, TX)
|
| Appl. No.:
|
022438 |
| Filed:
|
February 12, 1998 |
| Current U.S. Class: |
175/296; 175/299 |
| Intern'l Class: |
E21B 004/14 |
| Field of Search: |
175/296,299,105,305,306
173/73,208
|
References Cited
U.S. Patent Documents
| 3898815 | Aug., 1975 | Young | 175/321.
|
| 3946819 | Mar., 1976 | Hipp | 175/296.
|
| 4111271 | Sep., 1978 | Perkins | 175/297.
|
| 4462471 | Jul., 1984 | Hipp | 175/296.
|
| 4702325 | Oct., 1987 | Hipp | 173/64.
|
| 4958691 | Sep., 1990 | Hipp | 175/296.
|
| 5007479 | Apr., 1991 | Pleasants et al. | 175/297.
|
| 5156223 | Oct., 1992 | Hipp | 175/296.
|
| 5562170 | Oct., 1996 | Wolfer et al. | 175/296.
|
| 5595244 | Jan., 1997 | Roberts | 175/296.
|
| 5722495 | Mar., 1998 | Rear | 175/296.
|
Primary Examiner: Tsay; Frank S.
Claims
I claim:
1. A well tool apparatus for use with an elongated pipe string that can
load the tool transmitting impact thereto and with a flow bore for
transmitting pressurized fluid to the tool and wherein the tool can be
used during drilling, jarring or impacting in a well bore, comprising:
a) a tool housing having an upper end portion connectable to said tool
housing and in fluid communication with the lower end of a pipe string,
the housing having at least one fluid chamber therein for receiving
pressurized fluid transmitted from the pipe string thereto;
b) a tubular stem having a flow channel therethrough communicating with the
fluid chamber, the stem telescopically received by said housing for
relative reciprocal movement therewith between a first unloaded position
and a second loaded position, the stem having a valve seat thereon;
c) an impact receptive working member attached during use to one end of
said tubular stem for movement therewith between said first and second
positions, wherein impact is transmitted to the working member in the
second impact position so that the working member can be used during
drilling, jarring or impacting in the well bore;
d) a valve carried in said housing for controlling the flow of pressurized
fluid in the fluid chamber, said valve being reciprocally movable therein
between first and second positions;
e) said valve being operable to relieve fluid pressure within the fluid
chamber responsive to predetermined movement of said stem relative to said
housing, permitting relative movement of said stem and housing into said
second position when the valve seals the valve seat; and
f) a shock absorbing member positioned within the fluid chamber and in
between the working member and tool housing for reducing stresses in the
working member and tool housing that are generated during impact.
2. The well tool apparatus of claim 1 wherein the shock absorbing member is
an annular cushioning pad.
3. The well tool apparatus of claim 2 wherein the shock absorbing member is
an annular pad that surrounds the stem.
4. The well tool apparatus of claim 1 wherein the shock absorbing member is
of a material that is softer than the materials of the housing and stem.
5. The well tool apparatus of claim 4 wherein the shock absorbing member is
brass and the housing is steel.
6. The well tool apparatus of claim 4 wherein the shock absorbing member is
brass and the stem is steel.
7. The well tool apparatus of claim 4 wherein the shock absorbing member is
a composite material.
8. The well tool apparatus of claim 1 wherein the shock absorbing member is
positioned to absorb both compressive and tensile stresses of the working
member.
9. The well tool apparatus of claim 1 wherein the shock absorbing member is
positioned in between an annular shoulder of the stem and an annular
shoulder of the tool housing.
10. The well tool apparatus of claim 1 wherein the shock absorbing member
is an annular cushioning pad with a central opening that receives the
stem.
11. An impact, driven well tool for use with an elongated tubular pipe
string having a central flow conveying bore for channeling pressurized
fluid to the tool, comprising:
a) an elongated longitudinally extending tool body having means for
connecting the tool body to the pipe string;
b) a fluid chamber in the tool body in fluid communication with the pipe
string bore;
c) a stem reciprocally movable within the tool body in a telescoping
fashion, the stem having a lower end portion for carrying a working
member;
d) a pressure responsive valve for controlling relative movement of the
stem and tool body; and
e) a shock absorbing member positioned in between the stem and tool body
for reducing stresses in the stem during reciprocal movement of the stem.
12. The well tool apparatus of claim 11 wherein the shock absorbing member
is an annular cushioning pad.
13. The well tool apparatus of claim 11 wherein the shock absorbing member
is of a material that is softer than the materials of the tool body and
stem.
14. The well tool apparatus of claim 13 wherein the shock absorbing member
is brass and the working member is steel.
15. The well tool apparatus of claim 13 wherein the shock absorbing member
is a composite or metalic material.
16. The well tool apparatus of claim 11 wherein the shock absorbing member
is positioned to absorb both compressive and tensile stresses.
17. The well tool apparatus of claim 11 wherein the shock absorbing member
is positioned in between an annular shoulder of the stem and an annular
shoulder of the tool body.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A "MICROFICHE APPENDIX"
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to downhole oil well tools namely
run on a pipe string, impact, drilling, or jarring type downhole oil well
tools, and more particularly, to a fluid operated tool for use in well
bores wherein an anti-chatter switch prevents valve chatter when running
into the well bore.
2. General Background of the Invention
In downhole well operation, there is often a need for jarring or impact
devices. For example, in work over operations using a pipe string such as
coil tubing or snubbing equipment, it is necessary to provide downward
jarring impact at the bottom of the string to enable the string to pass
obstructions or otherwise enter the well. During fishing operations or
other operations, such as opening restriction (i.e., collapsed tubing) it
is sometimes necessary to apply upward jarring or impact forces at the
bottom of the string if the fishing tool or the like becomes stuck.
In prior U.S. Pat. No. 3,946,819, naming the applicant herein as patentee,
there is disclosed a fluid operated well tool adapted to deliver downward
jarring forces when the tool encounters obstructions. The tool of my prior
U.S. Pat. No. 3,946,819, generally includes a housing with a tubular stem
member telescopically received in the housing for relative reciprocal
movement between a first terminal position and a second terminal position
in response to fluid pressure in the housing. The lower portion of the
housing is formed to define a downwardly facing hammer and the stem member
includes an upwardly facing anvil which is positioned to be struck by the
hammer. The tool includes a valve assembly that is responsive to
predetermined movement of the stem member toward the second terminal
position to relieve fluid pressure and permit the stem member to return to
the first terminal position. When the valve assembly relieves fluid
pressure, the hammer moves into abrupt striking contact with the anvil.
The tool of prior U.S. Pat. No. 3,946,819, is effective in providing
downward repetitive blows. The tool of the '819 patent will not produce
upwardly directed blows.
In prior U.S. Pat. No. 4,462,471, naming the applicant herein as patentee,
there is provided a bidirectional fluid operated jarring apparatus that
produces jarring forces in either the upward or downward direction. The
jarring apparatus was used to provide upward or downward impact forces as
desired downhole without removing the tool from the well bore for
modification. The device provides downward jarring forces when the tool is
in compression, as when pipe weight is being applied downwardly on the
tool, and produces strong upward forces when is in tension, as when the
tool is being pulled upwardly.
In U.S. Pat. No. 4,462,471, there is disclosed a jarring or drilling
mechanism that may be adapted to provide upward and downward blows. The
mechanism of the '471 patent includes a housing having opposed axially
spaced apart hammer surfaces slidingly mounted within the housing between
the anvil surfaces. A spring is provided for urging the hammer upwardly.
When it is desired to use the mechanism of the '471 patent for jarring, a
valve including a closure and a compression spring is dropped down the
string to the mechanism.
In general, the mechanism of the '471 patent operates by fluid pressure
acting on the valve and hammer to urge the valve and hammer axially
downwardly until the downward movement of the valve is stopped, preferably
by the full compression of the valve spring. When the downward movement of
the valve stops, the seal between the valve and the hammer is broken and
the valve moves axially upwardly.
The direction jarring of the mechanism of the '471 patent is determined by
the relationship between the fluid pressure and the strength of the spring
that urges the hammer upwardly. Normally, the mechanism is adapted for
upward jarring. When the valve opens, the hammer moves upwardly to strike
the downwardly facing anvil surface of the housing.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a well tool apparatus for use with an
elongated pipe string that can load the tool transmitting impact thereto
and with a flow bore for transmitting pressurized fluid to the tool.
The apparatus includes a tool housing that is connectable to the lower end
of a pipe string so that it is in fluid communication with the pipe
string. The tool housing defines at least one fluid chamber for receiving
therein pressurized fluid that is transmitted from the pipe string.
A tubular stem having a flow channel therethrough communicates with the
fluid chamber, the stem telescopically received by the housing for
relative reciprocal movement therewith between a first "pressured up"
unloaded position and a second "impact" loaded position, the stem having a
valve seat thereon.
An impact receptive working member is attached during use to one end of the
tubular stem for movement therewith between first and second positions.
Impact is transmitted to the working member in a second impact position.
A valve is carried in the housing for controlling the flow of pressurized
fluid in the fluid chamber and reciprocally movable therein between first
and second positions. The valve is operable to relieve fluid pressure
within the fluid chamber responsive to a predetermined movement of the
stem relative to the housing, permitting relative movement of the stem and
housing into the second impact position when the valve seals the valve
seat.
An anti-chatter switch is disposed within the fluid chamber for separating
the valve and valve seat when flow is at a first minimal preset flow rate.
The anti-chatter switch preferably includes a sleeve that surrounds a
valving member.
The valve has an enlarged upper portion and the anti-chatter switch
includes a sleeve that surrounds the valving member below the enlarged
upper end portion of the valve.
The anti-chatter switch includes a sleeve that surrounds the valve and a
spring is positioned around the valve and above the sleeve.
A pair of springs can be positioned respectively above and below the sleeve
including an upper spring with end portions that engage the valving member
and sleeve, and a lower spring with end portions that engage the sleeve
and the tubular stem.
The tubular stem is an elongated member having upper and lower end portions
and a valve seat at the upper end portion of the stem. The stem and
valving member are movable downwardly within the tool housing with fluid
pressure when the valve seats upon the valve seat, forming a seal
therewith.
When the tool is lowered into the well, it is neither in tension nor
compression. But as the springs that deliver the energy for the upward
blow are preloaded (compressed) between the piston and the housing during
assembly, the piston is predetermined to rest at the top of its stroke.
The normal resting for the dart places the valving member very close to
seat. Therefore, any fluid pumped through the tool pulls the valving
member on to the seat. Piston begins to move down due to pressure build up
in chamber. Piston pulls dart down with it as they are locked together by
differential pressure across the seat.
As dart moves downward it compress spring. When the upward forces building
in the spring become greater than the force holding valving member to
valve seat, the seal is broken. Dart moves upward and piston follows
closely urged by spring. The cycle begins again, resulting in chatter and
seat wear.
BRIEF DESCRIPTION OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the
present invention, reference should be had to the following detailed
description, read in conjunction with the following drawings, wherein like
reference numerals denote like elements and wherein:
FIG. 1 is a sectional elevational view of the preferred embodiment of the
apparatus of the present invention shown in circulating position with the
valving member removed from the valve seat as when running into and out of
the well bore;
FIG. 2 is a sectional elevational of the preferred embodiment of the
apparatus of the present invention shown once the flow has collapsed the
spring, and the valving member seated upon the valve seat portion of the
tool body;
FIGS. 3 and 4 are fragmentary elevational views of the preferred embodiment
of the apparatus of the present invention showing details of the valve,
sleeves, and spring portions; and
FIGS. 5-6 are sectional elevational views of a second embodiment of the
apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show the preferred embodiment of the apparatus of the present
invention designated generally by the numeral 10 in FIGS. 1 and 2. Well
tool 10 includes an elongated tool body 11 having a proximal or upper end
12 and a distal or lower end 13. A tool bore 14 extends the full length of
the tool body 11 for circulating fluid through the tool body 11 and in
between its end portions 12, 13. Valving member 15 is slidably disposed
within bore 14 as shown in FIGS. 1 and 2.
The valving member 15 moves from an upper position (FIG. 1) to a lower
position (FIG. 2). In the upper position, a valving member end portion 18
of valve 15 is removed from seat 19. The valving member end portion 18 can
be either hemispherically shaped or flat. In the lower position shown in
FIG. 2, the valving member 15 surface 18 seats upon the valve seat 19
forming a closure therewith. In FIG. 1, a spring 23 of adjustable rate
holds the valving member 15 off the valve seat 19 to allow through tool
circulation into and out of the oil and gas well at a preset minimal flow
rate. When the tool 10 is lowered into the wall, it is in neither tension
nor compression. The springs that deliver the energy for the upward blow
are preloaded (compressed) between the piston and the housing. The piston
is predetermined to rest at the top of its stroke. The normal resting
position for the valving member 15 or "dart" places valve surface 18 very
close to seat 19.
The spring 23 collapses to permit the valving member 15 to seat upon the
valve seat 19 as shown in FIG. 2. As fluid is pumped through the tool body
11 via bore 14, valving member 15 travels from the initial position of
FIG. 1 to the sealed position upon seat 19 in FIG. 2. Then, piston 20
begins to move down due to pressure build up in bore 14 above valving
member 15 and seat 19. Piston 20 and valving member 15 move down together
as differential pressure builds up above seat 19. As valving member 15
moves further down, spring 23 becomes more and more compressed. When the
upward forces building in the spring become greater than the force holding
valving member 18 to valve seat 19, the seal is broken. Dart 15 moves
upward and piston 20 follows closely urged by spring 33. The cycle begins
again, resulting in chatter and seat wear.
The present invention solves this problem by providing an anti-chatter
switch arrangement that includes sleeve 26 and its spring 25 for holding
the valving member 15 off the seat 19 to allow through tool circulation
into and out of the well.
In FIGS. 3-4, valving member 15 has an annular shoulder 16 that receives
the upper end of coil spring 23. Coil spring 23 bottoms against upper
annular surface 27 of sleeve 26. The sleeve 26 has an enlarged diameter
cylindrically-shaped upper end portion 26A and a smaller diameter
cylindrically-shaped lower section 26B. Annular shoulder 28 defines the
interface between enlarged diameter section 26A and smaller diameter
section 26B.
Valving member 15 has a lower end portion 17 with hemispherically-shaped
valve surface 18. The hemispherically-shaped valve surface 18 can form a
closure with valve seat 19 at the upper end of piston 20. The piston 20
provides a cylindrically-shaped open ended flow bore 21 for communicating
with the flow bore 14.
Coil spring 23 extends from surface 16 of valve member 15 to surface 27 of
sleeve 26. Coil spring 25 extends from surface 31 of annular sleeve 22 to
annular surface 28 of sleeve 26. The sleeve lower end 29 has an annular
surface 30 that engages the surface 31 of annular sleeve 24 as shown in
FIG. 2 once a predetermined flow rate is attained and spring 25 collapses.
The springs 23 and 25 are of such an adjustable spring rate that they hold
the valving member 15 off seat 19 to allow through tool circulation.
In FIG. 2, that predetermined spring rate has been overcome by flow through
the tool body in the direction of arrow 32 in FIG. 2. This permits the
valving member 15 and more particularly its valve surface 18 to seat upon
the seat 19 permitting the apparatus 10 to run. By separating the valve
surface 18 from seat 19 when running into the well bore, any chatter
between the valve member 15 and the piston 20 is prevented.
In FIGS. 5 and 6, a second embodiment of the apparatus of the present
invention is shown, designated generally by the numeral 10A. In FIGS. 5
and 6, the valving member 15 seats at surface 18 when fluid flow through
bore 14 pushes down on the valving member. As with the embodiment of FIGS.
1-3, piston 20 and valving member 15 separate when the upward forces
building in spring 23 become greater than the force holding valving member
18 to valve seat 19 breaking seal. Then, valving member 15 moves upwardly
urged by spring 23 and piston 20 moves upwardly urged by spring 33.
The lower end 34 of piston 20 is enlarged, having an annular shoulder 35
that is shaped to register against and strike annular surface 36 of tool
body 11, creating an upward jarring blow.
In FIG. 5, removable, replaceable annular shock member 37 forms a shock
absorbing interface that lessens metal fatigue in piston 34 at surface 35
and in housing 11 at surface 36. The annular member 37 is of a material
that is softer than the material used to construct piston 20 and housing
11.
The following is a list of suitable parts and materials for the various
elements of the preferred embodiment of the present invention.
______________________________________
Part Number Description
______________________________________
10 well tool
11 tool body
12 upper end
13 lower end
14 flow bore
15 valving member
16 annular shoulder
17 lower end
18 valve surface
19 valve seat
20 piston
21 piston bore
22 sleeve
23 spring
24 annular sleeve
25 spring
26 sleeve
26A larger diameter section
26B smaller diameter section
27 annular surface
28 annular surface
29 sleeve lower end
30 annular surface
31 annular surface
32 arrow
33 spring
34 lower end
35 annular shoulder
36 annular surface
37 annular shock member
______________________________________
The foregoing embodiments are presented by way of example only; the scope
of the present invention is to be limited only by the following claims.
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